1. Field of the Invention
The present invention relates to a drawer, and more particularly to a locking/unlocking apparatus for a drawer.
2. Description of the Prior Art
Referring to FIG. 1, a first conventional automatic unlocking apparatus for drawer slide rails is provided with a top fastener 83 and a fastening element 54 on an external slide rail 81 and an inner surface of a pull rod 82. The top fastener 83 includes a main body 832 and loading plate 831 centrally extending along one side the main body 832. The main body 832 is provided at each of two opposite sides thereof with a protruding cylinder 8321 on which an elastic element 85 is mounted. A fixing fastener 86 is mounted on the loading plate 831 and provided with a hook (not shown) on the inner surface thereof, and a guiding cylinder 861 at a distal end thereof. The hook is movably engaged in the main body 832. A sliding sleeve assembly 87 is provided at both ends thereof with two sleeves 871 connected to the elastic elements 85. The main body of the sliding sleeve assembly 87 is disposed under the loading plate 831 and allowed to side along the slide rails of the loading plate 831. The fastening element 84 is provided with a guiding portion (not shown) and a shaft seat (not shown). The slide rails can be locked and unlocked easily by pressing the pull rod 82.
Referring to FIG. 2, a second conventional automatic locking apparatus for drawer slide rails is also disposed between an external slide rail 92 and an internal slide rail 91. The automatic locking apparatus comprises a guiding block 93 cooperating with a spring 94, a moving element 95, a buffer element 96, a first protruding element 97 and a second protruding element 98, offering an automatic locking function.
However, no matter how the unlocking or locking apparatus for drawer slide rails are designed, they have a common defect that the user cannot tell if the drawer is in a locking or an unlocking state from the outside, so that once the user pulls the drawer which is in the locking state by a large force accidentally, the slide rails or the automatic locking apparatus will be damaged inevitably.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.